“Melissa has been on a high-protein, low carb diet,” said a source. “She’s been making small changes and seeing big results.”

McCarthy’s weight loss motivation was a desire to be healthy for her daughters, Vivian and Georgette, with husband Ben Falcone.

“Melissa realized she wasn’t being as healthy as she could be,” said a friend. “She wants to set a good example for her kids and she wants to be around to become a grandmother too.”

Sources said McCarthy has no desire to be super-skinny, but merely wants to be healthier.

“Melissa knows that fans love her big and beautiful, and she’s not obsessed with dieting,” said the insider. “She’s just looking for a happy medium.”

McCarthy, who has been overweight most of her life, said she had tried many times to lose weight on various diets. With her low carb diet, it appears Melissa may soon reach her weight loss goals. McCarthy will roll out a plus-size clothing line this fall.

Other celebrities who have lost dramatic amounts of weight on low-carb diets include Kim Kardashian, Megan Fox and Tim McGraw, who lost 40 pounds with the Paleo diet and CrossFit workouts.